1. Technical Field
The present invention relates to a lock device which prevents a work machine of a construction machine from being tilted by the weight thereof. Especially, the present invention relates to a lock device which prevents a boom of a backhoe work machine from being rotated downward by the weight thereof.
2. Background Art
Conventionally, there is well known a so-called tractor loader backhoe constructed so that a loader is attached to a front portion of a traveling vehicle and a backhoe is attached to the rear portion thereof. With regard to such a kind of a tractor loader backhoe, a side column supporting a boom is standingly provided on a side frame at the front portion of the tractor, a bucket is supported at the tip of the boom, and the boom and the bucket can be rocked respectively by hydraulic cylinders, whereby a front loader is constructed. A boom is supported in the rear portion of the tractor so as to be rotatable vertically and laterally, an arm is supported at the tip of the boom so as to be rotatable vertically, a bucket is supported at the tip of the arm so as to be rotatable vertically, and each of them can be rotated by a hydraulic cylinder, whereby a backhoe is constructed.
The front loader is operated by an operation part arranged at a side of a seat. The backhoe is operated by a lever or the like provided on an operation column standingly provided on a frame of the rear portion while the seat is reversed longitudinally.
The tractor loader backhoe travels by wheels so that the tractor loader backhoe can travel at relatively high speed. At the time of traveling, if the loader or the backhoe which is a work machine is fallen by vibration, leak of pressure oil or the like, the travel may be hindered. Then, there is well known an art for locking the work machine at the time of not operating the work machine (for example, see the Patent Literature 1).
Patent Literature 1: the Japanese Patent Laid Open Gazette 2004-360331